In-ground lawn sprinklers are used to distribute water to a lawn. They are typically fed from an underground water line from which a vertical extension riser is attached. Attached to the riser is the head of the sprinkler, the sprinkler head having attached at its uppermost portion a stem that typically includes an extending member having a nozzle that can extend, under water pressure, to spray the lawn.
For proper watering, it is important to maintain the sprinkler head at the proper level with respect to the lawn. After the sprinkler system is installed, the lawn may rise, as mulch or new soil is added. Raising the sprinkler is typically done by adjusting the length of the riser pipe or adding extensions between the riser and the head. However, because the sprinkler head/riser joint is well below the level of the stem, which is typically at or near the grass level, digging is often required to effect this extension.
In the past, others, such as Rainbird, have provided a 6" stem member extension threaded internally at one end and externally at the other. This 6" extension is designed to fit where the nozzle of the extendable stem member screws into the top of the extendable stem member. The nozzle is unscrewed and the 6" extender is screwed into where the nozzle was originally screwed (the top of the extendable stem member). The nozzle is then threaded into the removed end of the extension to give a 6" rise to the nozzle as it sits above the cap of the stem. However, this 6" extension often stands above the surrounding grass and is in danger of being damaged by lawnmowers. Further, it prevents complete retraction of the nozzle into the head body. That is, even with the stem member in a retracted position (no water pressure in the head), the 6" extension raises the nozzle 6" above the stem cap.
What is needed is a simple, inexpensive, and heretofore unavailable means to elevate the stem of the sprinkler above the head body so as to increase the height of the stem above the head body to adjust the height of the stem so it is proper with respect to the ground around it.